1. Field of the Invention
This invention relates to dry good material feeding devices which use an auger for dispensing or conveying powders and bulk dry materials. More particularly, this invention relates to an auger drive assembly having special shaft sealing means and wherein the assembly can be quickly taken apart and removed for inspection and cleaning.
2. Description of the Prior Art
Dry good material feeders of the type which are manufactured at Tecnetics Industries, Inc. of St. Paul, Minn., which is the assignee of this application, commonly include a hopper having an inclined storage area and a lower cylindrical portion for housing a rotating auger. The rotating auger conveys dry material such as a powdered food product from the inclined holding area through a cylindrical passage to a space outside of the hopper. A drive assembly is typically provided for the auger at the end of the auger which is opposite from the housing opening through which the dry material is conveyed.
When feeders of this kind are used to dispense or convey dry food products, special consideration must be given to the sanitary aspects of the feeder design. For example, the feeders may feature all stainless steel construction and a food-grade polyurethane hopper so that repeated wash downs are not a problem. Also, the hoppers are designed so that they have no cracks or ledges to collect material, and the entire assembly is engineered for quick disassembly for cleaning and repair purposes.
It is known that some type of seal must be placed between the drive mechanism and the rotating auger so that the dry material being conveyed does not escape into the drive mechanism. The problems encountered with drive shaft seals of this kind, and an improved sealing arrangement, are discussed and disclosed in the Harold J. Kilts U.S. Pat. No. 5,110,015, issued May 5, 1992, also assigned to Tecnetics Industries, Inc. Those discussions and disclosures are incorporated herein by reference.
A particular problem arises when dry good material feeding devices of this kind are used to dispense or convey food products used for human consumption. Government regulations require that all materials used in construction of the feeder must meet certain standards for cleanliness and sanitation. It is also necessary to be able to quickly and easily disassemble the unit, including the auger drive assembly, to permit it to be inspected and cleaned. The seal for the drive shaft must not only prevent the dry material from escaping into the drive mechanism but it must also be constructed of a material which will conform to government standards. Heretofore, a dry good material feeding device for dispensing or conveying food products used for human consumption and which will fully meet government standards including approval for food grade 3A has not been available to the industry. Specific drawbacks of prior art feeders have included the sealing arrangement, the material from which the seal is made, and the ease of disassembling, cleaning and inspecting the auger drive mechanism.